Paint compositions from cataltti



Patented Jan. 17, 1950 um TED STATES PATENT rorrzlcs :COMPOSIZCIONS FROM CATALYTI- CALLY-CDNJUGATED OILS =Arthur Lew-is, "Helen A. 'Moser, and John-C. :Goman, :Pie;oria,-- :Ill., assignors to :the United States of America asrepresented by the Score- :tarfy of agriculture No Drawing. Application June 4,;19i1fi, Serial No. 674,159

6 Claims.

'(Granted under the act of March 3; 1883,5115 amended April 30, 1928; 3370 -.G. 15.7.)

:a, method of improving ertain 'filmnmperties of these coating pompositions: Mor sp ifi al y, it relates to a method cit-reducing tacks-in eutside paints which are formulated from catalytically conjugated vegetable oils.

In patent application Serial No. 564,500, a. method for improving the drying properties-of vegetable oils by treatment with certain types of catalysts is described. These catalysts effect a shift of unsaturated bonds in the polyunsaturated acid radicals in glyceride oils from the-monconjugated to the conjugated position. One of the better catalysts which effects this improvement in drying properties is activated nickel. supported on activated carbon black. Hereinythis catalyst is referred to as nickel-carbon-catalyst, and the oils produced from it, as NOI'COIIO'lrS, with the s referring to the soybean oil, or as nickel-carbon-conjugated oils.

One of the main disadvantages of prior soy bean oil paints is the tendency of the coatings to remain tacky for long periods of time. This phenomenon may be termed residual tack and is due to slow drying properties of soybean oil paints and it impairs the value of the coating, especially since :dust and adhere to the surfaces. Another disadvantage which characterizes prior soybean oil paints is the tendency of the coatings to soften and revert to a fluid 101' semi-liquid condition in environments of higher humidities and temperatures such as usually prevail during summer months. When softened thus, the coatings retain imbedded dust and dirt, and their durability is greatly reduced due :to the stresses and strains produced by .iinternal movements of the "filmsfilhis'phenomenon iOf softening may be termed "flatter-taro and .is more or less {independent of the initial *drying -.characteristics of the coatings. .llEor example, a

The residual tack emayibeso'.prolonged;and/or :the after-tack" develop :so rapidlythat the coating is not absolutely :tack ff-ree for periods of .many months. pMoreovergthe after-tack, :being a condition which oe'curs ?more :readily under .certain :enviromnen'tal conditions, as previously :described, "may recur after having disappeared.

.Nickel carbon conjugated ,oils, "when used in paint films, exhibit zaigreatly reduced period of residual tack as described :in the impending application referred .to :previously. Nevertheless these coating :have a marked tendency :to -.soften or revert to a semi-fluid condition under conditions of higher atmospheric 'humid-ities and temconjugation, were exposed at 45 F. facing south coating may dry rapidly with'iittleorno residual tack, and subsequently develop after-tack to a for 30-days. The panels coveredwithpaint films containing Norconol-:S were much darker than the panels covered wi-h ,paint films containing alkali-refined soybean oil. It is reasonable "to assume that this difference in darkness was caused by the differen'ce in'tackiness of the .films on the panels. The films were cleaned, but with "some of the pigments, it was impossible to wash enough dirt from panel to :give a ,c'leanwhite film. However, on rcontinued outdoor :exposure :ifor 30 'more days, the :eleaned .films from the paints containingaNorconol-S again became much darker and dirtier than the ifilms from paints containing alkali-refined soybean oil. It is certainly evident that the mickehcarbon-conjugated soybean oil exhibited tack which :did not disappear .even after prolonged exposure. ,As the exposure of thepanels was continuedthe weatherin of the film 'beganto ,affectthe amount of dirt adhering. "However, "with most pigments the 'N0lCOl101-S frlm'swere still darker, after 12 months exposure, than the films "prepared with alkali refined' soybean "oil.

We have discovered that this-:objectionable tackiness in the "paints 'fformulated fir-om the nickeI-carbon-conjugated soybean oil can be reduced substantially by the incorporation of calcium oxide or calcium hydroxide. Certain other oxides and salts of the alkaline-earth metals, and

equal to that of raw linseed oil paints containing basic carbonate of white lead. Interestingly enough, calcium oxide did improve reflectance of the non-break soybean oil paints, but it did not of the sukfgl'oup P group II the periodi? table improve the reflectance values of raw linseed oil and certain flattmg agents, improve the dirt colpaints gg i l g g of i othgr Wi Similar paints were prepared using barium, g i g z g g z g zf g 22:5 g i calcium, zinc, and magnesium oxide to the extent 1 h rates, were not as good as the calcium oxide or gag gfg jgi g z igfi 1 2 $3: hydroxide in reducing the dirt collection. Al- 1 7 o d g m t though paints formulated with titanium oxide, panes prepare compara pam 8 without calcium oxide or. other alkaline-earth from nlckel'caflion'comugatjed soybfaa'n oxides, began to show much reduced dirt collecbreak soybean and raw lmseed tion after one years exposure, the dirt collection 15 in the first six months was very objectionable. ia g z f jg The improvement in dirt collection using calw 2 m fi ms con mung me a w on as cium oxide was studied by substituting the calcium oxide or other material undergoing test for D a portion of the pigment used. Paints containing g ffg g' gj Non-break Raw '75 percent pigment by weight, and percent oil gstedsoybean 25? jfi by weight were prepared, using basic carbonate White lead as the main pigment with approximately one part of oil drier per 19 parts of oil, gggig and 0, 2%, or 5 /2 percent of calcium oxide, cal- 25 3 BCWL+5$ percent ZnO. so e3 68 cium stearate or aluminum stearate in pigment. g ggf ggg gg Nickel-carbon-conjugated oils, non-break soybean oflfland raw ImSFQd' 011s were used In All readings are averages of five readings taken after outdoor formulations. The dllBIS used in these studies exposure of films or three months and six days. were lead and manganese. Paints were coated on conditioned cedar panels, and three coats were T bl I shows h w th films of Norconol-S applied. Hunter reflectance readings were taken containin 5 percent magnesium oxide or calafter 96 hours of interior exposure, and 9 days cium oxide were much superior in the reflectance and 115 days of outdoor exposure. Table I shows measurements to the other films and to the conthe results of the reflectance measurements. trol containing no added oxide.

Table I.- Oomparative reflectance readings from white paint films Nickelcarbon-conig gggg Rawllnseed jugated soy- 011 bean oil A B o A B o A B c 1 AllBCWL 90 7s 41 87 so 55 85 so as 2 BCWL+2% percent CaO ss 9o 65 so as 58 s2 90 as a BCWL+51/ percent 0210.". so 92 as 81 so as s3 90 e3 4 BCWL+2% percent Al. Stealateu so 84 so 90 a4 52 s4 90 as 5 BCWL+5% percent Al. Stearata. 87 so 50 9o s3 s2 s3 92 e5 6 BOW +2% percent Ce Stearatc" 9O 81 92 82 88 91 62 7 BCWL+5% percent Ca Stearate 88 82 48 90 82 50 85 94 Column A-Average oi five readings taken before outdoor exposure of films; films air dried for 96 hours.

days.

Column C-Average of five readings taken after outdoor exposure of films for3 months and 24 days.

1 BOWL-Basic carbonate white lead.

Prior to outdoor exposure, Norconol-S paints without added calcium oxide have higher reflectances than either of the comparable non-break soybean and linseed oil paints. On continued exposure for over three months, films of Norconol-S paints, with only basic carbonate of white lead as a pigment, have the lowest reflectance values of any of the paints in this series, indicating the presence of tack in the films caused by a softening or reversion to a semi-fluid condition. Norconol-S paint fllms containing 2% or 5 percent of calcium oxide as pigment were substantially better in dirt collection than comparable paints from non-break soybean oil after three months exposure as measured by reflectance. The reflectance values-for the Norconol-S paints containing calcium oxide were j approximately Table III.Comparative reflectance readings from wh te paint films of Norconol-S Nickel-carbonconjugated soybean oil 1 1 All BOWL 49 2 OaO refined nickel-carbon conjugated soybean oil plus basic carbonate white lead.. 50 44 3 BCWL+%pcrcent CaO 62 48 4 BCWL+1 percent CaO 67 47 5 BOWL-F2 percent OaO .i 78 52 6 BOWL-F595 percent 0210 81 68 7 BCWL-Hl percent CaO 6. 8 BCWL+5 percent Z 70 55 1 Columns A- and B are averages of five readings taken after outdoor exposures of 1% and 5 months, respectively. v

Table=I-II shows how reflectance values-of. these paint=films change-with the increase in. percent age of calcium oxide in the pigment. Apparently; a-maximumin reflectance value-of the films tested-in this seriesoccurs at approximately 53/ percent calcium oxide.

Comparisons should-not be made between the reflectance valuesin the three tables, since they report on-refiectances obtained from outdoor exposure made under slightly difierent conditions, and the dirt collection should not be expected to be, uniform, at different periods. during the year.

The following examples taken from Kass, Radlove, and Cowarr-application Serial No'. 564,500, filedNovember 21, 1944, referred to above,, illusetrate the. preparation of the mekel-carboncatalysts andithe nickel-carbon-con-jugatedasoybean oil. Eznamplel 192- grams-of nickel formate are dissclvedwin 5,500 ml. of hot,,distilledwater: The solution is filtered and added to 210 gramspf activated carbon. A suitablegactivated'carbon maybe pre pared from sulfite wastes resulting from sul'fitepulping process by burning at 900 C. followed by neutralizing the resulting carbon with hydrochloric acid, and copiously washing it to remove excess acids, salts, and other impurities. This suspension is evaporated by boiling until a to percent moisture content is obtained. The catalyst composition is then ready for activation by reduction with hydrogen.

Example II 116 grams of nickelous nitrate are dissolve in 160 ml. of distilled water and thoroughly ground with grams of activated carbon. The mixture is added slowly to a solution of 68 grams of ammonium carbonate in 400 ml. of water, mixed, and filtered. The filter cake is washed with 200 milliliters of distilled water, dried at 100 to C., and ground to a fine powder. The catalyst composition is then ready for activation by re-' duction with hydrogen.

The catalyst compositions may be activated by reduction with hydrogen in the following manner:

Example III 24 grams (dry weight basis) of catalyst comfposition, prepared by the method of Example I, are placed in a 500 ml. three-neck round-bottom flask fitted with a Hershberg stirrer constructed of nichrome wire, an inlet gas tube reaching as close to the bottom of the flask as possible, a funnel with a stopcock, a thermometer, and a gas outlet tube. Hydrogen is passed over the catalyst composition, and the temperature raised rapidly to about 360 C. The composition is then stirred intimately with the hydrogen at 360:40" C. for two hours. The hydrogen is replaced with carbon dioxide, and the flask and contents are cooled to below C. The catalyst may be used immediately or stored in vegetable oil under carbon dioxide, nitrogen, or other protective gas. In the reduction of the nickel in the catalyst, other types of apparatus can be used, but proper precautions must be observed to obtain intimate contact between catalyst composition and the hydrogen and to exclude oxygen.

As ilustrative of the manner in which our process of conjugation may be carried out, the following examples are given. In these examples, conjugation is given in percentages obtained by the use of ultraviolet absorption data from pure matenialseandt trom. the isomerized oils by use of a Beokmamspectrophetometen =Eor:diene cone triene conjugation, the absorption Ofoz-GIBOStGaIiG acid, (ihll lfi qctadecatrienoic. acid.) which is acl is. ,olow'tomakeany appreciable effect on th. percenta Foranalysis; sample of isomerized oilwas: dilu e 150-2. m1; weapo -a Solvent and the absorption of the solution determined in a Beckman spectrophotometer. In an absorption of 300 at 2300 A. and 150 at 2700 A. were.

obtained, the percentages of conjugation would be 26.1 diene and 8.1 triene, respectively. The values given arenot corrected for the difierence between equivalent weights of glyceride and conjugated acids used for standards. However, this difierence presumably is partially compensated by slight differences in the absorption of conjugated isomers produced by our catalyst.

The contact between the catalyst and the reactant may be accomplished by any suitable means that will effect intimate mixture, such as agitation or by causing the liquid material to flow through, or to be in contact with, the catalyst which may be adequately packed or maintained on supports in suitable apparatus.

Example IV Example V To 25 g. of the nickel-activated carbon catalysts (prepared as in Example II or III) is added 300 g. of soybean oil, and the reaction mixture is heated at a temperature of 178-180 C. for 4.0 hours. The reaction mixture was then cooled and filtered. The refractive index is increased by 0.0067, and the viscosity increased from 0.5 to 0.85 poise at 25 C. The color before the conjugation was 10, while after it was 2 (Gardner scale). Analysis by means of the Beckman spectrophotometer indicates 32.3 percent diene and 2.6 percent triene conjugation.

Having thus described our invention, we claim:

1. A paint mixture consisting essentially of basic carbonate white lead pigment; soy bean oil that has been conjugated by treatment in the presence of nickel-carbon catalyst; the said lead pigment and oil being in the weight ratio of about 3 of pigment to 1 of oil; paint drier; and calcium h absorption of; 9;12;115=octadecatrienoic oxide in the proportion of, 2%.percentto .-11 percent of the basic carbonate white lead; 2. The paint mixture of claiml in which the calcium oxide is present in the proportion of 5 percent of the basic carbonate white lead.

3. A paint mixture consisting essentially of basic carbonate white lead pigment; soy bean oil vehicle conjugated by treatment inthe presence of nickel-carbon catalyst; a paint drier; a; reflectance improving substance taken from the group consisting of oxides andhydroxides ofalkaline-earth metals andmagnesium in the proportion of 2% to 11 percent of the basic carbonate white lead the said lead pigment and oifbeing in the weight ratio of about3 of pigment to 1 of oil. J

4. A paint mixture consisting essentially of a pigment; soybean oil that: has been conjugated by treatment in the presence-of a nickel-carbon catalyst; a paint drier; a reflectance improving substance taken from the groupconsisting of oxides and hydroxides of alkaline-earth. metals and magnesium in anamount 2%,to. llpercent of the said pigment the said pigment and oil being in the weight ratio of about 3 of 1 of oil.

8. 5. 'The paint mixture of claim 4 in which the reflectance improving substance is calcium,

hydroxide.

6. The paint mixture of claim 4 in which the. reflectance improving substance is magnesium oxide.

ARTHUR J. LEWIS. HELEN A. MOSER. JOHN C. COWAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS OTHER REFERENCES I Gregory: Uses and Applications of Chemicals pigment 25 and Related Materials, vol. I, page 141. 

1. A PAINT MIXTURE CONSISTING ESSENTIALLY OF BASIC CARBONATE WHITE LEAD PIGMENT; SOY BEAN OIL THAT HAS BEEN CONJUGATED BY TREATMENT IN THE PRESENCE OF NICKEL-CARBON CATALYST; THE SAID LEAD PIGMENT AND OIL BEING IN THE WEIGHT RATIO OF ABOUT 3 OF PIGMENT TO 1 OF OIL; PAINT DRIER; AND CALCIUM OXIDE IN THE PROPORTION OF 2 3/4 PERCENT TO 11 PERCENT OF THE BASIC CARBONATE WHITE LEAD. 